code: def test_angle_real():
      fun = lambda x: np.angle(x)
      d_fun = lambda x: grad(fun)(x)
      check_grads(fun)(npr.rand())
      check_grads(d_fun)(npr.rand())
  
file_path: autograd/tests/test_complex.py
imports: from __future__ import absolute_import
  import autograd.numpy
  import autograd.numpy.random
  from autograd.test_util import check_grads
  from autograd import grad
label_desc: Use image node_id 3 for calling a global function with example usage: test_angle_real() without return types